Chapter 2.2-Multimedia Storage Techniques

8/9/2019 Chapter 2.2-Multimedia Storage Techniques

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XML (Extensible Markup Language

XML is a markup language.

XML stands for eXtensible Markup Language.

The XML standard was created by W3C to provide an

easy to use and standardized way to store self-describing

data (self-describing data is data that describes both itscontent and its structure).


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Communication Between Application

XML is nothing by itself. XML is more of a "common ground"

standard. The main benefit of XML is that you can use it to take datafrom a program like MSSQL (Microsoft SQL), convert it into XML,

then share that XML with a slough of other programs and platforms

What makes XML truly powerful is the international acceptance it

has received.

Many individuals and corporations have put forth their hard work

to make XML interfaces for databases, programming, office

application, mobile phones and more.


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Applications of XML

* Cell Phones - XML data is sent to some cellphones. The data is then formatted by the specificationof the cell phone software designer to display text or

images, and even to play sounds!

* File Converters - Many applications have beenwritten to convert existing documents into the XMLstandard. An example is a PDF to XML converter.

* VoiceXML - Converts XML documents into an

audio format so that you can listen to an XMLdocument.


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Internet Explorer 6.0 supports viewing XML files.

You can download IE 6.0 from Microsoft's Website. InternetExplorer 6.0 has special color coding the make XML documents

easier to read.

Firefox XML Viewer: Firefox has some of the same features as

Internet Explorer. You can download Mozilla's Firefox fromMozilla.com.

Free XML Editors:

There are many free XML editors available for download on the

internet. Here are a few we have found useful:* XML Cooktop

* XML Mind Standard Edition

* Pete's XML Editor

Free XML Viewer


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XML Syntax:

XML Code:

RobertA+

LenardA-


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XML code.

This line with special symbols and attributes is what isreferred to as the XML declaration. It simply stateswhat version of XML you are using and the type ofencoding you are using

XML Tag

The XML tag is very similar to that of the HTML tag.Each element is marked with an opening tag and a

closing tag.RobertA+


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XML Elements

They contain the opening and closing tags, child

elements, and data.

Robert

A+

XML Attribute

An attribute appears within the opening tag of

an element.

Robert

A+


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XML Attribute Quotation Usage

The types of quotes that you use around your

attribute values is entirely up to you. Both thesingle quote (') and the double quote (") are

perfectly fine to use in your XML documents.


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XML Comment Syntax

Robert

A+

Lenard

A-


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XML Commenting out XML

To temporarily remove some XML code from your XML document.

Robert

A+


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XML PrologThe prolog is an optional component of the XML

document. If included, the prolog must be appearbefore the root element. A prolog consists of two parts:

the XML declaration and the Document TypeDeclaration (DTD). Depending on your needs, you can

choose to include both, either, or neither of these itemsin your XML document.


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* !DOCTYPE - Tell the XML processor that this

piece of code defines the Document Type Definition* html - Specifies the root element of the XMLdocument. Here our example is an HTML file, which has

as the root element.

* PUBLIC - Specifies that this a publicly availableDTD.

* "-//W3C//D..." - The definition of the publicdocument. Describing this is beyond the scope of this

tutorial.* "http://www.w3.org/..." - The physical location of

the DTD. Notice how this DTD resides on w3's servers.


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When an element appears within another element, it issaid that the inner element is "nested". The term nestedcan be related directly to the word "nest". If an element

is nested within another element, then it is surrounded,

protected, or encapsulated by the outer elementExample A

XML Nesting


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Example B

All elements are closed in the order that they wereopened. Those elements which were opened first are

closed last.Example B is what example A must look like to be awell-formed XML document.


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XML was designed to be a very robust markup language that could be used in many different

applications. However, with XML being able to communicate between so many different

platforms, there is one problem that tends to occur.

Welcome to my Health Resource

6ft

155 lbs

Two very different elements that want to use the same name: body. The solution to this problem is

to create XML Namespaces,

XML Namespaces


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XML Documents: Valid Versus Well-Formed

In XML, there are three ways to measure a

document's validity: valid, well-formed, and broken.* One Root Element - The XML document mayonly have one root element. See our Root ElementLesson for more information.

* Proper Nesting - XML elements must be closedin the order they are opened. See our Nesting Lessonfor more information.

* Well-Formed Entities - Any entities that are

referenced in the document must also be well-formed.See our Entity Lesson for more information.


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Broken XML Code:

Mr. GarciaHello there! How are we today?

Well-Formed XML Code:

Mr. Garcia

Hello there! How are we today?

The error in the first example was:The document suffers from improper

nesting. The body element was opened inside the to element, yet body was

not closed before the to element was closed!


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XML Tree: The great benefit about XMLis that the document itself describes the

structure of data.

inventory is the root element.


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XML - The Tree Structure


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Structure of an XML Document


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Tree Structure

.....


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E tit R f


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Entity References

If you place a character like "


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XML(Table)

XP th Fi di I f ti


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XPath - Finding Information

XPath is the solution to finding information in an XMLdocument. XPath uses expressions to find elements,attributes, and other information in your XML. If you

have an XML document that contained a bunch of yourfavorite books, each with author children elements, youcan use a one line XPath expression to find all theauthors of your favorite books!

The most common place people might see XPathexpressions are in XSLT (Extensible StylesheetLanguage Transformation).


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f


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S f XML D


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S f XML D


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St t f XML D t


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XML is Used to Create New Internet Languages

A lot of new Internet languages are created with XML.

Here are some examples:

* XHTML the latest version of HTML

* WSDL for describing available web services

* WAP and WML as markup languages for handheld devices

* RSS languages for news feeds* RDF and OWL for describing resources and ontology

* SMIL for describing multimedia for the web

SMIL 2 0 XML for Web Multimedia


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SMIL 2.0 XML for Web MultimediaSMIL stands for Synchronized MultimediaIntegration Language

SMIL is pronounced "smile"

SMIL is a language for describing audiovisual

presentations

SMIL is easy to learn and understand

SMIL is an HTML-like language

SMIL is written in XML

SMIL presentations can be written using a text-

editor

SMIL is a W3C standard

What Can SMIL Do?


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What Can SMIL Do?

Although plug-ins and media players have the ability to

show many different types of media with varyingsupport for interaction, only SMIL offers the ability to

define the presentation in the form of text as a script.This feature could be called media composition.

Also, SMIL offers accessibility options and powerfulfeatures not present in other media players.

Implementing SMIL


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Implementing SMILCommon SMIL implementations

* Internet or Intranet presentations.

* Slide show presentations.

* Presentations which link to other SMIL files.

* Presentations which have Control buttons (stop, start, next, ...)

* Defining sequences and duration of multimedia elements.

* Defining position and visibility of multimedia elements.

* Displaying multiple media types such as audio, video, text

* Displaying multiple files at the same time.

* Displaying files from multiple web servers.

Currently, SMIL's most widespread usage is with MMS. MMS (Multimedia

Messaging System) is a mobile device technology

Guidelines and Rules


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SMIL documents look a lot like HTML. SMIL files need to be written according to

the following rules:

* SMIL documents must follow the XML rules of well-formedness.

* SMIL tags are case sensitive.

* All SMIL tags are written with lowercase letters.* SMIL documents must start with a tag and end with a closing

tag.

* SMIL documents must contain a tag for storing the contents of the

presentation.

* SMIL documents can have a element (like HTML) for storing

metadata information about the document itself, as well as presentation layout

information.


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...

...

Image to our presentation


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Copy and paste this URL


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Copy and paste this URL,"http://html.tucows.com/designer/basictut/example1.s

mil" into your SMIL parser, i.e., RealPlayer,

QuickTime, for an example of the SMIL presentationcreated

Multiple Regions


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p g

We placed the new region, "text", 200 pixels from the top and 50 pixels from the left so that

it's centered in our presentation.


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Below is a table with the possible values we can give tothe fit attribute.


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We want to make the tucows.gif image fit perfectly

within the region, so we would add fit="fill" to the textregion. Below is an example.

Time ControlY l t l h l t t i i f di t b di l f b


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You can also control how long you want a certain piece of media to be display for by

using the "dur" attribute. This attribute takes a numerical value in seconds with the letter

"s" after the number. For example, lets say we want the cows to be displayed for 10

seconds and the rest of the images for only 5. We would add "dur="10s"" to the cow's img

tag and "dur="5s"" to the rest of the img tags. Below is what our code would look like.


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This should display the TUCOWS text image, then the

HTML text image during a span of 10 seconds.

SMIL for phones


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MMS uses SMIL to define the layout of multimedia

content.SMIL was adopted because it was a well-defined,standard language to describe the layout and timing of

the content inside MMS messages.